Detect result use of prop assignment

Author: janedbal

src/Visitor/PropertyWriteVisitor.php

@@ -90,6 +90,10 @@ private function markPropertyWrites(Expr $expr): void
     {
         if ($this->isFetch($expr)) { // $this->prop =
             $expr->setAttribute(self::IS_PROPERTY_WRITE, true);
+
+            if (!$this->hasUnusedResult()) {
+                $expr->setAttribute(self::IS_PROPERTY_WRITE_AND_READ, true);
+            }
         }
 
         if ($expr instanceof List_) { // [$this->first, $this->last] =
@@ -99,13 +103,21 @@ private function markPropertyWrites(Expr $expr): void
                 }
                 if ($this->isFetch($item->value)) {
                     $item->value->setAttribute(self::IS_PROPERTY_WRITE, true);
+
+                    if (!$this->hasUnusedResult()) {
+                        $item->value->setAttribute(self::IS_PROPERTY_WRITE_AND_READ, true);
+                    }
                 }
             }
         }
 
         while ($expr instanceof ArrayDimFetch) { // $this->array[] =
             if ($this->isFetch($expr->var)) {
                 $expr->var->setAttribute(self::IS_PROPERTY_WRITE, true);
+
+                if (!$this->hasUnusedResult()) {
+                    $expr->var->setAttribute(self::IS_PROPERTY_WRITE_AND_READ, true);
+                }
                 break;
             }
             $expr = $expr->var;

tests/Rule/data/properties/write-array.php

@@ -6,11 +6,13 @@ class Test
 {
     public array $array; // error: Property PropertyWriteArray\Test::array is never read
     public array $array2; // error: Property PropertyWriteArray\Test::array2 is never read
+    public array $array3;
 
 }
 
-function test(): void {
+function test() {
     $test = new Test();
     $test->array['name'] = 'John';
     $test->array2['more']['name'] = 'John';
+    return $test->array3[] = 1;
 }

tests/Rule/data/properties/write-coalesce.php

@@ -4,9 +4,11 @@
 
 class Coalesce
 {
-    public $prop; // error: Property PropertyWriteCoalesce\Coalesce::prop is never read
+    public $prop1; // error: Property PropertyWriteCoalesce\Coalesce::prop1 is never read
+    public $prop2;
 }
 
-function test(Coalesce $c): void {
-    $c->prop ??= 1;
+function test(Coalesce $c) {
+    $c->prop1 ??= 1;
+    return $c->prop2 ??= 2;
 }

tests/Rule/data/properties/write-multi.php

@@ -6,12 +6,12 @@ class Person
 {
     public string $first; // error: Property PropertyMultiWrite\Person::first is never read
     public string $last; // error: Property PropertyMultiWrite\Person::last is never read
-
-    public function __construct(string $name) {
-        [$this->first, $this->last] = explode(' ', $name, 2);
-    }
+    public string $city;
+    public string $zip;
+    public string $country;
 }
 
-function test(): void {
-    new Person('John Doe');
+function test(Person $p) {
+    [$p->first, $p->last] = ['John', 'Doe'];
+    return [$p->city, $p->zip, $p->country] = ['Prague', '10300', 'CZ'];
 }